Asian Noodles: Science, Technology, and Processing

In Asian Noodles: Science, Technology and Processing, international experts review the current knowledge and offer comprehensive cutting-edge coverage on Asian noodles unmatchable in any publication. The authors cover an array of topics including breeding for noodle wheat, noodle flour milling, noodle flour quality control and analysis, noodle processing, sensory and instrumental measurements of noodle quality, the effects of wheat factors on noodle quality, packaging and storage, nutritional fortification of noodle products, noodle flavor seasoning, and noodle plant setup and management.

• Language: English
• Publisher: Wiley
• Release date: Feb 16, 2011
• ISBN: 9781118074350

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CHAPTER 1

BREEDING NOODLE WHEAT IN CHINA

ZHONGHU HE, XIANCHUN, XIA AND YAN ZHANG

1.1 INTRODUCTION

China is the largest wheat producer and consumer in the world, and wheat ranks as the third leading grain crop in China after rice and maize. Wheat products are the major staple foods consumed in northern China although its consumption in southern China is also increasing rapidly. In 2007, the national wheat area, average yield, and production were 23.7 million ha, 4608 kg/ha, and 109 million metric tons, respectively. However, more than 70% of Chinese wheat is produced in five provinces— Henan, Shandong, Hebei, Anhui, and Jiangsu. The wheat-growing area has been divided into ten major agroecological zones as indicated in Figure 1.1, based on wheat types, varietal reactions to temperature, moisture, biotic and abiotic stresses, and wheat-growing seasons (He et al. 2001). On the basis of sowing dates, autumn-sown wheat accounts for more than 90% of production and acreage. Winter and facultative wheats, sown in the Northern China Plain (Zone I) and Yellow and Huai River Valleys (Zone II), contribute around 70% of production. Autumn-sown, spring habit wheat, planted in both the Middle and Low Yangtze Valleys (Zone III) and Southwestern China (Zone IV), contributes around 25% of production. Spring-sown spring wheat is mostly planted in Northeastern and Northwestern China (Zones VI, VII, and VIII) and makes up around 5% of production.

FIGURE 1.1 Chinese wheat production map: I, Northern Winter Wheat Zone; II, Yellow and Huai River Valleys Facultative Wheat Zone; III, Middle and Low Yangtze Valleys Autumn-Sown Spring Wheat Zone; IV, Southwestern Autumn-Sown Spring Wheat Zone; V, Southern Autumn-Sown Spring Wheat Zone; VI, Northeastern Spring Wheat Zone; VII, Northern Spring Wheat Zone; VIII, Northwestern Spring Wheat Zone; IX, Qinghai–Tibetan Plateau Spring–Winter Wheat Zone; X, Xinjiang Winter-Spring Wheat Zone.

From the establishment of the People’s Republic of China in 1949 to the present, wheat continues to play an important role in food production. Great progress has been achieved in wheat production during the last 60 years. Average wheat yield has increased 1.9% annually, and production has increased more than sixfold. Many factors have contributed to the significant increase of average yield, including adoption of improved varieties, extension of high-yielding cultivation technology, increased use of fertilizers and irrigation, expansion of farm mechanization, and improvement of rural policy. Agricultural policy reform in the early 1980s greatly stimulated wheat production, and 123 million metric tons of harvested grain was recorded in 1997. Wheat area, however, has declined from 30 million ha to around 23 million ha since 2000, largely due to the policy of increasing crop diversity, elimination of guaranteed pricing policies in south China and spring wheat regions, and lower profitability of wheat production in comparison to cash crops.

Around 50% of production is marketed as commercial wheat and stored in governmental grain stations, and the remaining 50% is stored and consumed by individual farmers. The annual wheat consumption is around 100–105 million metric tons. Currently, around 80% of wheat is used for food production, 10% for feed, 5% for seed, and the remaining 5% for industrial use. As listed in Table 1.1, traditional Chinese foods, such as steamed bread and noodles, account for around 85% of food products, and Western-style bread and soft wheat products, such as cookies, cakes, and biscuits, make up the remaining 15% although they are increasing rapidly, particularly in the urban areas. There are many types of noodles consumed across China; however, fresh noodles, instant noodles, and dry white Chinese noodles are the most popular types as presented in Table 1.2.

TABLE 1.1 Percentage of Various Wheat Products Consumed in China.

TABLE 1.2 Percentage of Various Noodles Consumed in China.

The international community has a confused concept of Chinese noodles. Yellow alkaline noodles (YANs) are commonly referred to as Chinese noodles in English, yet they are consumed mostly in Japan and other southeastern Asian countries, while a different type of yellow alkaline noodle is consumed in parts of northwestern and southwestern China, including Gansu and Sichuan provinces. Most of the previous studies reported in international literature focused on Japanese and Korean style udon noodles and yellow alkaline noodles, but the quality aspects of traditional Chinese noodles remain largely unexplored.

Yield improvement has been the top priority for wheat breeding and production, largely due to high population pressure. However, as living standards have improved since the 1980s, market demand for high-quality wheat has increased rapidly. Therefore, quality improvement has become an important objective for wheat breeding programs across China. Genetic improvement for noodle quality is very important to serve domestic market needs although a lot of effort has been focused on pan bread-making quality. The Chinese Academy of Agricultural Science (CAAS) and the International Maize and Wheat Improvement Center (CIMMYT) have worked together on Chinese wheat quality improvement during the last 10 years and have been especially focused on dry white Chinese noodles (DWCNs) and raw Chinese noodles (RCNs), due to popularity and high commercial values. The objective of this chapter is to review the progress achieved in noodle quality improvement, including establishment of standardized laboratory testing, identification of traits and molecular markers associated with noodle quality, and development of noodle quality varieties.

1.2 NOODLE QUALITY TESTING AND CULTIVAR DEVELOPMENT

1.2.1 Laboratory Preparation

Chinese noodles have been consumed over several thousand years across various parts of China, but scientific documentation on noodle quality has been very limited in China until quite recently. A standardized laboratory method for assessing noodle quality is crucial in wheat breeding programs targeted at developing noodle quality varieties. Our experience indicates that DWCNs and RCNs show great similarity in preparation and evaluation although drying is needed for DWCNs. Noodles are mainly made from wheat flour, water, and other ingredients such as common salt. In Chinese languages, noodles made from nonwheat flours, such as rice, mung beans, and sweet potatoes, are named Fen (see Chapter 16 for more details); only noodles made from wheat and buckwheat are named Miantiao.

1.2.1.1 Background Information

A bright white color is preferred for Chinese white noodles (CWNs), and flour extraction rates have a significant effect on noodle color but not on noodle texture. Flours with extraction rates of 60–70% are commonly used to produce this type of noodles although, occasionally, a 40% extraction rate is employed to produce very high-quality noodle flour.

Noodle properties are significantly affected by the amount of added water in dough preparation. High-quality noodles were prepared within a narrow range of water addition that was ±2 percentage points from optimum (Oh et al. 1985, 1986). Therefore, it is crucial to determine the optimum water additions for different types of wheat varieties in noodle testing programs. However, there are different opinions on optimum water additions for laboratory preparation of CWNs. A 44% water absorption (WA), measured by farinograph, was recommended as the optimum water addition in the official method (SB/T10137-1993) released by the Chinese Ministry of Commerce (1993. Optimum water addition varied among varieties; that is, optimum water addition was 50% WA for high WA varieties (WA ≥ 65%), 55% WA for medium WA varieties (55% < WA < 65%), and 60% WA for low WA varieties (WA ≤ 55%) (Liu et al. 2002). Measurement of WA with the farinograph is a labor- and time-consuming activity and is not a practical laboratory procedure for breeding programs. An optimum water addition of 30–35% of the flour weight was recommended (Zhang et al. 1998); the optimum water addition should be determined by targeting a final dough water content of 35% (Lei et al. 2004). Therefore, much more work is needed to determine the optimum water addition for testing different varieties in breeding programs.

Salt was the main additive for DWCNs since it leads to avoidance of strand breakage and improves sensory evaluation scores, particularly for noodles made from low-quality flour. However, salt is not commonly added to RCNs in China. In general, a salty taste is not preferred, and the water after cooking noodles is traditionally served as a drink. Salt is often added in laboratory noodle processing procedures, but the amounts vary greatly, ranging from zero to 2%.

1.2.1.2 Establishment of Noodle Preparation Formula

To establish a standardized noodle preparation formula, the effects of flour extraction rate (50%, 60%, 70%), added water (33%, 35%, 37%), including the moisture available in the flour, and salt concentration (0%, 1%, 2%) on color and texture of RCN were investigated using flour samples from five leading Chinese winter wheat varieties in our laboratory (Ye et al. 2009). Analysis of variance indicated that variety, flour extraction rate, level of water addition, salt concentration, and their interactions all had significant effects on the color of raw noodle sheets and textural properties of RCNs. However, variety and water addition were more important sources of variation than flour extraction rate and salt concentration. The brightness (L*) and redness (a*) values of raw noodle sheets were significantly reduced and increased, respectively, as the flour extraction rate was increased from 50% to 70%, and noodle scores were slightly higher at a flour extraction rate of 50%.

Noodle sheet brightness (L*) at 2 hours declined as water addition increased, and a significant improvement was observed for noodle appearance, firmness, viscoelasticity, smoothness, and total score as water addition increased from 33% to 37%, as indicated in Table 1.3 (data from three varieties). However, during noodle preparation, 37% water addition gave excessive absorption in all five flour samples, particularly Zhongyou 9507 and Yumai 18. This resulted in slack doughs that were too extensible to maintain the same thickness of the noodle sheet and resulted in increased problems in noodle sheeting and cutting. Water addition at 35% appeared to produce optimum absorption for Jimai 20, Jimai 21, and Wenmai 6, which is slightly more acceptable than for Zhongyou 9507 and Yumai 18. Therefore, 35% water addition was considered optimal for laboratory preparation of CWNs.

TABLE 1.3 Effect of Water Addition on Raw Noodle Sheet Color Sensory Parameters of Raw Chinese Noodlesa.

Brightness of raw noodle sheets and firmness and viscoelasticity of cooked noodles were significantly improved, but noodle flavor significantly deteriorated as salt concentration increased from zero to 2%; 1% salt produced the highest noodle score, as indicated in Table 1.4 (data from three varieties). Thus, the recommended composition for laboratory preparation of RCNs is 60% flour extraction, 35% water addition, and 1% salt concentration.

TABLE 1.4 Effect of Salt Concentration on Raw Noodle Sheet Color and Sensory Parameters of Chinese White Noodlesa.

1.2.1.3 Noodle Preparation

A standardized laboratory noodle preparation protocol was established (Zhang et al. 2005a,b, 2007). Noodle dough was prepared by mixing 200 g flour with enough water to achieve 35% water absorption in a Hobart N50 mixer (Hobart, North York, Canada) for 30 seconds using slow mixing speed (speed position 1 of the mixer). This first mixing step produced dough crumbs that were aggregated by hand-kneading and then mixed for 30 seconds at slow speed, followed by mixing at high speed (speed 2) for 2 minutes and then at slow speed for 2 minutes. The final stiff dough obtained was passed through the sheeting rolls of a laboratory noodle machine (Xongying MT40-1, Hebei, China) and sheeted four times using the 4-mm roll gap setting. The sheeted dough was rested in a plastic bag for 30 minutes at room temperature, and then successively sheeted using 3-mm, 2-mm, and 1-mm roll gap settings. The final dough sheet was cut to produce 3-mm wide and 25-cm long, 1.5-mm thick noodle strips. Raw noodle strips (150 g) were boiled for 6 minutes in 2 L of boiling water. After boiling, the noodles were rinsed by hand under running tap water for 1 minute.

Drying is needed for DWCNs, and the raw fresh noodles were kept in a chamber for 10 hours at 40 °C and 75% relative humidity, and then dried another 10 hours at laboratory room conditions. DWCN strips (150 g) were boiled for 12 minutes in 2 L of boiling water.

1.2.2 Sensory Evaluation of Chinese White Noodles

Desirable attributes of cooked Chinese white noodles include white and bright color, smooth appearance, medium level of firmness, good viscoelasticity (resistance to bite and not sticking to teeth), and smooth feel in the mouth, with a pleasant taste and flavor. Chinese white noodles differ from Japanese udon noodles in several aspects. Color is not as white and creamy as udon, indicating a difference in ash content and protein content. Chinese noodles are firmer than udon, indicating a difference in gluten and starch composition. They are more elastic and chewy than udon, also indicating a difference in gluten and starch composition.

Although the official method for the sensory evaluation of DWCNs (SB/T10137-1993, Chinese Ministry of Commerce, 1993) was released in 1993, it needs a lot of improvement. The scoring system (Table 1.5) has three problems. First, most panels have difficulty in evaluating elasticity and stickiness separately since the system definitions of elasticity (elastic and cohesive when chewed) and stickiness (noodles should not stick to teeth when chewed) lead the panels to evaluate similar characteristics. Our unpublished data indicated that the correlation coefficient between elasticity and stickiness ranges from 0.70 to 0.85 in various experiments. Second, the elasticity and stickiness parameters are each assigned 25 points, the highest score given to an individual noodle trait. This seems too high, especially considering the difficulty of evaluating the two traits separately, as defined above. Third, no reference sample was employed to evaluate the score for a testing sample, and score inconsistency occurred even when the panelists were well trained.

TABLE 1.5 Scoring System for White Salted Noodles in Various Countriesa

Therefore, we adopted the evaluation system used in Japan and other Asian countries for white salted noodles, with major modifications in the score assigned to each noodle trait, as shown in Table 1.5 (Zhang et al. 2005b). In this method, evaluation of elasticity and stickiness was combined into viscoelasticity. The weight given to each noodle trait was modified according to differences in consumer preferences for noodle attributes in China versus consumer preferences in Japan. Color was assigned a higher score (15) than in the previous Chinese method (10) but lower than in the Japanese method (20). The score assigned to appearance (10) was also lower than that in the Japanese method (15), because this parameter is less important for evaluating noodle quality in China. The score given to viscoelasticity (30) was lower than the combined value (25 + 25) assigned to elasticity and stickiness in the previous Chinese method. The score given to smoothness (15) was higher than in the previous method (5), because Chinese consumers believe the sensory mouthfeel, including smoothness and viscoelasticity, is essential for evaluating RCN quality. In addition to panel testing, other approaches were used to measure noodle parameters. The color of cooked noodles was closely associated with measurement by the Minolta CR 310, with r = 0.73. Hardness of texture profile analysis (TPA) using a Texture Analyzer was significantly associated with noodle total score, with r = 0.66 (Lei et al. 2004).

To improve consistency among panel members, a new scoring method was developed and presented in Table 1.6. In this method, each attribute was classified into seven classes (i.e., excellent, very good, good, fair, poor, very poor, and unacceptable), and a score was assigned to each class based on comparison with a reference sample at each panel session. A well-known commercial Xuehua flour, with 5% sweet potato starch added to it, showed a relatively good and stable noodle quality and each attribute had a good score. This flour blend was used as a reference sample in our evaluation. Panelists compared six parameters (i.e., color, appearance, firmness, smoothness, viscoelasticity, and taste–flavor) and assigned a score to each. To adapt to standard Chinese noodle-consumption style, noodles were evaluated using hot Chinese chicken soup prepared by dissolving two 10.5-g solid soup tablets (Knorr Co. Ltd.) in 1 L of hot water.

TABLE 1.6 Sensory Scoring System for Chinese Noodle Quality

1.2.3 Traits and Molecular Markers for Noodle Quality

1.2.3.1. Characterization of Chinese Wheat for Quality Traits

As can be seen in Table 1.7, Chinese wheat varieties and lines, on average, are characterized by acceptable protein content, but accompanied with weak medium gluten strength and poor extensibility, and substantial variation is presented for all quality traits. This is not unexpected since no selection was made on quality performance before the 1990s. Even at present, quality testing is only employed in the leading breeding programs. It is estimated that great progress could be achieved through breeding for DWCN quality given the wide variation of quality characteristics present in Chinese varieties and experimental germplasm.

TABLE 1.7 Mean, Standard Deviation, and Range of Grain Quality Traits for 104 Wheat Varieties Based on Averaged Data from Two Years and Two Locations

The mean, standard deviation, and range of DWCN quality parameters for 104 varieties and experimental lines, averaged from four growing environments, are presented in Table 1.8. As shown, there is wide variation in all noodle quality parameters, which most likely reflects the large variability in grain quality parameters of test materials. Thus, there is much room for improving the DWCN quality of Chinese wheats.

TABLE 1.8 Mean, Standard Deviation, and Range for Cooked Noodle Quality Performance of 104 Wheat Varieties Based on Averaged Data from Two Years and Two Locations

1.2.3.2. Traits Associated with Noodle Quality

A large number of varieties from different parts of China, Mexico, and Australia were used to establish the association between flour traits and noodle quality performance (Chen et al. 2007; He et al. 2004;; Liu et al. 2003; Zhang et al. 2005a,b). In general, flour from medium-hard to hard wheat with low ash content, high flour whiteness, medium protein content, medium to strong gluten type, and good starch viscosity is considered suitable for making Chinese noodles. Major traits associated with DWCN quality were identified (i.e., gluten strength and extensibility, starch viscosity, and flour color associated traits), as presented in Table 1.9. The association between SDS–sedimentation value, farinograph stability, and extensograph maximum resistance, extension area, and DWCN score fitted a quadratic regression model, accounting for 31.0%, 39.0%, 47.0%, and 37.0% of the DWCN score, respectively (Table 1.10) (He et al. 2004). The starch peak viscosity contributed positively to DWCN quality, with r = 0.57 (Figure 1.2). Flour ash content and PPO had a negative moderate effect on noodle color (Figure 1.3), while protein content and grain hardness were negatively associated with noodle color, appearance, and smoothness (Zhang et al. 2005b). There was a very high association between flour color grade (FCG) and L* value of flour–water slurry (r = −0.95) (Figure 1.4). Strong associations were also established between milling quality index (MQI) and FCG, L* values of dry flour, flour–water slurry, and white salted noodle sheet (Zhang et al. 2005a). Therefore, FCG can be used to predict noodle sheet color. To summarize, SDS–sedimentation value or mixing time from mixograph, RVA peak viscosity or flour swelling volume, polyphenol oxidase (PPO) activity, and yellow pigment content can be used to screen for DWCN quality in the early generations of a wheat breeding program.

TABLE 1.9 Noodle Quality Groups and Their Mean Wheat Quality Characteristics.

TABLE 1.10 Quadratic Regression Model Between DWCN Score and Four Grain Quality Traits

FIGURE 1.2 Association between RVA peak viscosity and DWCN score..

(Data source: He et al. 2004.)

FIGURE 1.3 Association between flour ash content and noodle color.

(Data source: Zhang et al. 2005.)

FIGURE 1.4 Relationship between flour color grade and L* value of flour–water slurry.

(Data source: Zhang et al. 2005.)

1.2.3.3 Molecular Markers Associated with Noodle Quality

Molecular markers have great potential to improve breeding efficiency if they can be combined with quality testing and conventional breeding technology. In addition to validating molecular makers from other programs around the world, we have started an active molecular marker development program for noodle quality improvement. Our approach is to clone genes, such as Psy 1 genes, on chromosomes 7A and 7B that are associated with yellow pigment and PPO genes at chromosomes 2A and 2D, develop functional markers based on the gene allelic variants, and then validate the markers with Chinese wheat varieties. Therefore, molecular markers developed in our program can be used efficiently in breeding programs.

Molecular and biochemical markers, such as Pinb-D1b (grain hardness), PPO 18, PPO 16, and PPO 29 (PPO activity), Psy-7A and Psy-7B (yellow pigment), Glu-A3d and Glu-B3d (gluten quality), and Wx-B1b (starch viscosity), are closely associated with noodle quality as presented in Table 1.11 (Briney et al. 1998; Chen et al. 2007; He et al. 2005, 2007, 2008, 2009; Sun et al. 2005). Use of these molecular markers can greatly improve the selection efficiency in early generations, and they can also be used to confirm the results from conventional quality testing in more advanced stages.

TABLE 1.11 Molecular Markers for Selection of Desirable Chinese Noodle Qualities

1.3 BREEDING FOR BETTER NOODLE QUALITY

A regional quality classification was released in 2002, based on the climate date (temperature/rainfall), soil type/farming system/ use of fertilizers, and quality data collected in China for the last 15 years (He et al. 2002). In general, three regions are recognized. (1) Winter and facultative wheat regions (including Zones I and II) (see Figure 1.1) focus on hard white and medium-hard types, targeting for bread, noodle, and steamed bread qualities. (2) Autumn-sown spring wheat regions (including Zones III, IV, and V) focus on red soft wheat; however, red medium-hard types for steamed bread and noodles quality are also recommended. Sprouting tolerance is needed due to the high rainfall environment. (3) Spring-sown spring wheat regions (including Zone VI, VII, and VIII) focus on red hard and medium-hard types, targeting bread, steamed bread, and noodles. Sprouting tolerance is also needed to ensure processing quality.

Breeding efforts in quality improvement started in the late 1980s and quality testing laboratories have been established in Beijing, Jinan, Zhengzhou, Yangling, and Harbin. The objectives of wheat quality improvement programs are to combine the high yielding potential and excellent processing quality. As stated previously, Chinese wheat is characterized by broad variation for all quality parameters; it has acceptable protein content but weak gluten strength, thus acceptable quality for manual production but inferior quality for mechanized production. Therefore, improvement in gluten strength was the primary objective for all products, including pan bread, noodles, and steamed bread although color is also important for noodles and steamed bread. Two approaches were employed to improve noodle quality. First, significant effort was put into screening current varieties and advanced lines to identify noodle varieties for production. Second, Chinese varieties with outstanding noodle quality or introductions from the United States, Canada, Australia, and CIMMYT are crossed with high-yielding Chinese wheats to develop new varieties with improved noodle quality. In addition to the final noodle testing, a number of analyses are employed to select for desirable noodle quality at various stages: gluten strength parameters (high molecular weight gluten subunit composition, absence of 1B/1R translocation, SDS or Zeleny sedimentation volume, and farinograph stability time), starch parameters (flour swelling volume and Rapid Visco Analyzer peak viscosity), biochemical and molecular markers for Wx-B1 null, and flour color parameters (PPO activity or yellow pigment). At present, breeding programs that target noodle quality improvement include the Chinese Academy of Agricultural Science (CAAS, Beijing), Shandong Academy of Agricultural Science (Jinan), Shandong Agricultural University (Taian), and Henan Academy of Agricultural Science (Zhengzhou). All four of these programs are located in winter and facultative wheat regions although efforts are also being put toward noodle quality improvement in other regions.

Progress on breeding better quality wheat has been reviewed in Chinese Wheat Improvement and Pedigree Analysis (Zhuang 2003). Varieties conferring improved noodle quality, based on the information from breeding programs, uniform quality testing nurseries managed by our own lab, and feedback from milling industries are listed in Table 1.12, and detailed information is presented below.

TABLE 1.12 List of Noodle Quality Varieties Released in China

Jing 9428, a soft kernel variety derived from Jing 411/German introduction, was released by the Beijing Seed Company in 2000. It was characterized by soft kernel, medium gluten strength, and very bright white flour and noodle color, thus resulting in outstanding noodle and dumpling quality. Its yield was close to the control variety Jing 411, but with big kernel size (thousand kernel weight 45 g) and red color, it has good sprouting tolerance. It has been a leading variety in Zone I (including Beijing, Tianjin, northern Hebei, and Shanxi) from 2000 to the present, with annual acreage of 130,000 ha, sharing 20% of the wheat area.

Zhongyou 9507, a reselection of outstanding pan bread quality variety Zhongzou 8131-1, was released by the Chinese Academy of Agricultural Science in 2001. It was characterized by high protein content, strong gluten quality, and very bright flour and noodle color, and thus had outstanding pan bread and noodle quality. Its yield was close to control variety Jingdong 8, with big kernel size (thousand kernel weight 45 g), good resistance to stripe rust and powdery mildew, and tolerance to high temperatures. It was released in Beijing, Tianjin, Hebei, Shanxi, and Xinjiang, with annual acreage of 60,000 ha. Its popularity was limited by the susceptibility to preharvest sprouting. It is interesting to observe that Zhongyou 9507 was originally a mixture of hard and soft kernels although the majority of kernels were hard type; then during seed production, the soft kernel became a dominant type. Reselections were made; thus, both hard and soft types were obtained.

Xiaoyan 6, a hard kernel variety, derived from St2422/464 crossed with Xiaoyan 96 following a laser treatment, was released by the Northwestern Botany Research Institute in 1980. It was characterized by high yield potential and wide adaptability, resistance to yellow rust, and tolerance to high temperatures. It was a leading variety in central Shaanxi for around 10 years in the 1980s, with an annual sowing area of 400,000 ha. In the late 1980s, it was identified as carrying good noodle and steamed bread qualities since it had medium gluten quality with excellent extensibility and bright white flour color. It also performed with good bread-making quality under a high-protein environment. It was recommended as an excellent quality variety in the 1990s. Xiaoyan 6 was widely used in breeding programs for quality improvement. PH-82-2, a reselection of Xiaoyan 6, was released in Shandong province in the early 1990s. Xiaoyan 54, another reselection of Xiaoyan 6, was released in Shaanxi province in 2000. All three cultivars performed with similar processing quality even though they were sown in different provinces.

Yannong 15, a soft kernel variety derived from St2422/464 crossed with Baiyoubao, was released by the Yantai Agricultural Research Institute in 1980. It was characterized by high yield potential and good lodging resistance and was identified as carrying good qualities for pan bread, noodles, and steamed bread due to its medium dough strength with excellent extensibility and bright white flour color. It has had an annual acreage of 130,000 ha from the 1980s to the present and was also recommended as a good quality variety in the 1990s. It was widely used to make noodle flour in Shandong province.

Jimai 19, a hard kernel variety derived from Lumai 13/Linfen 5064, was released by the Shandong Academy of Agricultural Sciences in 2001. It was characterized by high yield potential (7% better than the control variety) and excellent noodle quality. It has medium gluten strength, and excellent flour and noodle color. It has been a leading variety in Shandong province since 2002 with more than 800,000 ha per year. It was also sown in the provinces of Jiangsu, Anhui, Henan, and Hebei.

Jimai 20, a hard kernel variety, was derived from Lumai 14/Shandong 84187 by the Shandong Academy of Agricultural Science in 2003. It was characterized by strong gluten strength and excellent noodle color, thus conferring qualities for pan bread and noodles. It combined high yield potential, outstanding and consistent quality over various environments, and broad adaptation. It is a leading quality variety in the provinces of Shandong, Hebei, Jiangsu, and Anhui, with annual acreage of 1 million ha in 2008.

Yumai 34, a hard kernel variety, derived from Aifeng 3//Meng 201/Neuzucht/3/ Yumai 2, was released by the Zhengzhou Agricultural Research Institute in 1994. It was characterized by balanced dough properties and excellent flour and noodle color, thus conferring excellent qualities for pan bread and noodles. Yumai 34 combined high yield potential with 3.2% higher yield than control variety Yumai 18, outstanding and consistent quality over various environments, and broad adaptation. It has been a leading quality variety in Henan province since 1998, with annual acreage of 500,000 ha per year.

Yumai 47, a hard kernel variety derived from Yumai 2/Baiquan 3199, was released by the Henan Academy of Agricultural Science in 1997. It was characterized by medium to strong gluten strength, high starch viscosity, and bright white flour, thus conferring good noodle and pan bread qualities. Its yield was close to control variety Yumai 18, and it shows good resistance to powdery mildew. It has been extended as a good quality variety in Henan province from 2000 to the present, with annual acreage of 200,000 ha per year.

Yumai 49, a soft kernel variety derived from Wen 394A/Yumai 2, was released by the Xiangyun Agricultural Extension Station in 1998. It was characterized by high yield potential and good qualities for noodles and steamed bread largely due to its bright white product and slightly better gluten strength. It was a leading variety in the late 1990s in Henan province, with annual acreage of 670,000 ha per year.

Ningchun 4, a soft kernel variety derived from Sonora 64/Hongtu, was released by the Wheat Seed Production Station of Yongning County in Ningxia in 1981. It was characterized by high yield potential, good resistance to biotic and abiotic stresses, and broad adaptation. It was well known for its excellent noodle quality due to medium gluten strength and bright white color. At present, its commercial grain is widely used to produce the well-known Xuehua flour in Ningxia and Inner Mongolia. It has been the leading variety in the Northwestern Spring Wheat Zone covering Gansu, Ningxia, and parts of Inner Mongolia and Xinjiang from 1983 to the present, with the largest annual sowing acreage of 300,000 ha.

1.4 THE FUTURE

The improvement in grain yield has always been the top priority for Chinese wheat breeding programs, largely due to high population pressure. However, processing quality has become more and more important since the late 1990s, and farmers are unlikely to accept varieties conferring poor processing quality. Therefore, high grain yield and excellent industrial quality must be combined into new varieties, together with broad adaptation and resistance to various biotic and abiotic stresses. It is quite possible to combine high yield potential with excellent noodle quality, as exemplified by Jimai 19 and Yumai 34, since a medium level of protein content is needed to produce high-quality noodles. Although significant progress has been achieved in developing noodle varieties, there is still a long way to go to improve the overall noodle quality of Chinese varieties. Three approaches were recommended for improving noodle quality in the future.

First, noodle quality testing should be included as part of the variety development and release procedure; thus, varieties conferring outstanding noodle quality can be released. At present, only advanced lines with high yield potential are evaluated for end-use quality in most breeding programs. Strong gluten wheat for bread-making quality receives prime consideration in variety release, and it is acceptable if the yield reduction is less than 5% compared to the control variety. To promote noodle quality varieties, we suggest that varieties conferring outstanding noodle quality should be released if the yield performance is equivalent to the control variety.

Second, improvement of dough extensibility and starch viscosity is crucial for noodle quality breeding although dough strength and color are also important. Based on the quality data from six environments as presented in Table 1.13, the Australian varieties Hartog and Sunstate, which have excellent dough extensibility, had better noodle quality than the best noodle quality varieties from China. Priority has been given to improve dough strength since the beginning of the quality improvement program, and has thus resulted in improved quality wheat with unbalanced dough properties. Therefore, much more work is needed in the future to improve dough extensibility. It has been determined that starch viscosity is crucial for Chinese noodles; however, the frequency of Wx-B1 null type is very low in Chinese wheat, as presented in Table 1.14. Among the noodle varieties listed in Table 1.13, only Yumai 47 confers Wx-B1 null type. Therefore, integration of desirable genes into current varieties is needed, and both biochemical and molecular markers can play an important role in this area.

TABLE 1.13 Quality Performance of Selected Noodle Varieties, Averaged Data From Six Environments

TABLE 1.14 Distribution of Wx-B1 Null Genotypes in Different Chinese Wheat Regions

Third, the possibility of developing soft wheat varieties with medium to strong gluten quality for noodle quality should be explored. This type of germplasm is not uncommon in China, but is not available in countries with a long history of wheat quality improvement. Soft wheat with stronger gluten and exceptionally good brightness received very favorable evaluations by Asian noodle and mill technicians (Morris 1998), and this has been confirmed in China. Our data from two environments, as presented in Table 1.15, indicates that it is possible to develop such a variety type since the noodle quality of Eradu and Gamenya was highly preferred by Chinese consumers. As indicated in Table 1.13, Jing 9428, Yannong 15, Yumai 49, and Ningchun 4 belong to this type. Therefore, development of a variety with soft kernel wheat, medium to strong gluten strength, and good bright color could become an important objective for noodle quality improvement.

TABLE 1.15 Quality Performance of Selected Soft Kernel Varieties, Averaged Data from Two Environments

1.5 SUMMARY

Quality improvement has become a very important breeding objective in China and significant progress in noodle quality improvement has been achieved in the last 10 years. A standardized laboratory preparation and evaluation system for Chinese noodle quality has been established. The recommended composition for laboratory preparation of Chinese noodles is 60% flour extraction, 35% water addition, and 1% salt concentration. A modified scoring system and sensory scoring method were developed and employed, and consistency of noodle quality testing is much improved. The major traits conditioning Chinese noodle quality include gluten strength and extensibility, starch viscosity, yellow pigment, PPO activity, grain hardness, and protein content. SDS–sedimentation value, RVA peak viscosity, yellow pigment content, and PPO activity can be used as selection criteria in early generations. PPO genes at chromosomes 2A and 2D and Psy 1 genes at chromosomes 7A and 7B were cloned and STS markers were developed and validated, that is, Psy-7A and Psy-7B for yellow pigment, and PPO 18, PPO 16, and PPO 29 for PPO activity. Molecular markers for starch viscosity (Wx-B1 null) and grain hardness (Pinb-D1b) were also validated in Chinese wheats. Glu-A3d and Glu-B3d show slightly better noodle quality than the other alleles. Both conventional and molecular approaches have been employed in noodle quality improvement, and ten noodle quality varieties, such as Jimai 19, Jimai 20, Yumai 34, Xiaoyan 6, and Ningchun 4, were developed and extended as leading varieties. A combination of high yield potential with noodle quality is the key for successful varieties development. Three approaches were recommended for noodle quality improvement in the future: i.e. (1) integrating noodle quality testing into variety development and release procedures, (2) improving dough extensibility and starch viscosity, and (3) exploring the possibility of developing soft wheat varieties with medium to strong gluten quality for noodle quality.

REFERENCES

Briney, A., Wilson, R., Potter, R. H., Barclay, I., Crosbie, G., Appels, R., and Jones, M. G. K. A. 1998. PCR marker for selection of starch and potential noodle quality in wheat. Mol. Breeding 4: 427–433.

Chen, F., He, Z. H., Chen, D. S., Zhang, C. L., Zhang, Y., and Xia, X. C. 2007. Influence of puroindoline alleles on milling performance and qualities of Chinese noodles, steamed bread and pan bread in spring wheats. J. Cereal Sci. 45: 59–66.

Chinese Ministry of Commerce. 1993. Noodle flour, SB/T10137-1993.

He, Z. H., Rajaram, S., Xin, Z. Y., and Huang, G. Z. (eds). 2001. A History of Wheat Breeding in China. CIMMYT, Mexico, D. F., pp. 1–95.

He, Z. H., Lin, Z. J., Wang, L. J., Xiao, Z. M., Wan, F. S., and Zhuang, Q. S. 2002. Classification on Chinese wheat regions based on quality performance. Sci. Agric. Sinica 35(4): 359364 (in Chinese).

He, Z. H., Yang, J., Zhang, Y., Kuail, K. J., and Pena, R. J. 2004. Pan bread and dry white Chinese noodle quality in Chinese winter wheats. Euphytica 139: 257–267.

He, Z. H., Liu, L., Xia, X. C., Liu, J. J., and Pena, R. J. 2005. Composition of HMWand LMW glutenin subunits and their effects on dough properties, pan bread, and noodle quality of Chinese bread wheats. Cereal Chem. 82: 345–350.

He, X. Y., He, Z. H., Zhang, L. P., Sun, D. J., Morris, C. F., Furerst, E. P., and Xia, X. C. 2007. Allelic variation of polyphenol oxidase (PPO) genes located on chromosomes 2A and 2D and development of functional markers for the PPO genes in common wheat. TAG 115: 47–58.

He, X. Y., Zhang, W. L., He, Z. H., Wu, Y. P., Xiao, Y. G., Ma, C. X., and Xia, X. C. 2008. Characterization of phytoene synthase 1 gene (Psy 1) located on common wheat chromosome 7A and development of a functional marker. TAG 116: 213–221.

He, X. Y., He, Z. H., Ma, W., Appels, R., and Xia, X. C. 2009. Allelic variants of PSY1 genes in Chinese and CIMMYT wheat cultivars and development of functional markers. Mol. Breeding 23: 553–563.

Lei, J., Zhang, Y., Wang, D. S., Yan, J., and He, Z. H. 2004. Methods for evaluation of quality characteristics of dry white Chinese noodles. Sci. Agric. Sinica 37: 20002005 (in Chinese).

Liu, J. J., He, Z. H., Zhao, Z. D., Liu, A. F., Song, J. M., and Pena, R. J. 2002. Investigation on relationship between wheat quality traits and quality parameters of dry white Chinese noodles. Acta Agron Sin 28: 738742 (in Chinese).

Liu, J. J., He, Z. H., Zhao, Z. D., Pena, R. J., and Rajaram, S. 2003. Wheat quality traits and quality parameters of cooked dry white Chinese noodles. Euphytica 131: 147–154.

Morris, C. F. 1998. Evaluating the end-use quality of wheat breeding lines for suitability in Asia noodles. In: A. B. Blakeney and L. OBrien (eds.), Pacific People and Their Food. American Association of Cereal Chemists, St. Paul, MN, USA, pp. 91–100.

Oh, N. H., Seib, P. A., Ward, A. B., and Deyoe, C. W. 1985. Noodles IV. Influence of flour protein, extraction rate, and particle size, and starch damage on the quality characteristics of dry noodles. Cereal Chem. 62: 441–446.

Oh, N. H., Seib, P. A., Finney, K. F., and Pomeranz, Y. 1986. Noodles V. Determination of optimistic water absorption of flour to prepare oriental noodles. Cereal Chem. 63: 93–96.

Sun, D. J., He, Z. H., Xia, X. C., Zhang, L. P., Morris, C., Appels, R., Ma, W., and Wang, H. 2005. A novel STS marker for polyphenol oxidase activities in bread wheat. Mol. Breeding 16: 209–218.

Ye, Y. L., Zhang, Y., Yan, J., Zhang, Y., He, Z. H., Huang, S. D., and Quail, K. J. 2009. Effects of flour extraction rate, added water and salt on color and texture of Chinese white noodles. Cereal Chem. 86: 477–485.

Zhang, L.,Wang, X. Z., and Yue, Y. S. 1998. TOMbeing a new assessment method for Chinese noodle cooking quality and effects of wheat quality characteristics on it. J. Chinese Cereals Oils Assoc. 13(1): 4953 (in Chinese).

Zhuang, Q. S. (ed.) 2003. Chinese Wheat Improvement and Pedigree Analysis. China Agricultural Press, Beijing, China (in Chinese).

Zhang, Y., Kuail, K. J., Mugford, D. C., and He, Z. H. 2005a. Milling quality and white salt noodle color of Chinese winter wheat cultivars. Cereal Chem. 82: 633–638.

Zhang, Y., Nagamine, T., He, Z. H., Ge, X. X., Yoshida, H., and Pena, R. J. 2005b. Variation in quality traits in common wheat as related to Chinese fresh white noodle quality. Euphytica 141: 113–120.

Zhang, Y., Yan, J., Yoshida, H., Wang, D. S., Chen, D. S., Nagamine, T., Liu, J. J., and He, Z. H. 2007. Standardization of laboratory processing of Chinese white salted noodle and its sensory evaluation system. J. Triticeae Crops 27(1): 158165 (in Chinese).

Asian Noodles: Science, Technology, and Processing, Edited by Gary G. Hou Copyright © 2010 John Wiley & Sons, Inc.

CHAPTER 2

BREEDING FOR DUAL-PURPOSE HARD WHITE WHEAT IN THE UNITED STATES: NOODLES AND PAN BREAD

ARRON H. CARTER, CARL A. WALKER, and KIMBERLEE K. KIDWELL

2.1 INTRODUCTION

Hexaploid wheat (Triticum aestivum L.) is the primary food grain consumed directly by humans worldwide, and more land around the globe is devoted to the production of wheat than to any other commercial crop (Briggle and Curtis 1987). Wheat is well adapted to diverse climatic regions, and two growth habit types, winter (requires vernalization to flower) and spring (does not require vernalization), exist. Six market classes, which are distinguished by kernel hardness, grain color, head morphology, and in some cases growth habit, are in commercial production in the United States of America (USA), including soft white (SW), soft red winter (SRW), hard red winter (HRW), hard red spring (HRS), hard white (HW), and durum wheat (USDA-NAAS 2007). The end-use product goals for each wheat market class differ according to flour quality attributes. Flour extracted from hard red wheat (HRW and HRS) typically has strong gluten and is used for bread baking, whereas SW and SRW wheat have weak gluten and are used for making pastries, cookies, cakes, and crackers (Finney et al. 1987). Hard white cultivars are targeted to Pacific Rim consumers for noodles, steam breads, and white pan bread production. The domestic bread-baking industry often uses HW wheat as a replacement for HRW and HRS wheat. Since grain color, head type, hardness, growth habit, and several end-use quality parameters are simply inherited in wheat, these traits can easily be manipulated through plant breeding and selection (Allard 1999).

Breeding efforts to develop HW wheat cultivars are relatively new in the United States. A majority of the wheat breeding efforts across the United States have focused on developing red cultivars due to the difficulties of overcoming the problem of preharvest sprouting (PHS) in HW wheat. HW wheat is more prone to PHS than red wheat due to pleiotropic effects of genes controlling red-testa pigmentation on seed dormancy (Anderson et al. 1993). When the genes for red-testa pigmentation are present, PHS is reduced (Imtiaz et al. 2008). Preharvest sprouting damage often has deleterious effects on bread-making qualities, thus increasing the risk of producing white wheat (Groos et al. 2002). Reduced exposure of wheat grain to moisture at physiological maturity is essential to eliminate the risk of PHS. Low annual precipitation levels in the Pacific Northwest provide optimal growing environments for white wheat; whereas in high precipitation areas, such as the Midwest and Southeast regions of the United States, the risk of producing HW is high (Simpson 1990).

Sources of moderate tolerance/resistance to PHS are present in white wheat germplasm (Mares 1987; Derera 1989; Wu and Craver 1999); however, breeding for tolerance/resistance to PHS is difficult due to the polygenic nature and low heritability of the trait (Anderson et al. 1993). Resistance to PHS is quantitatively inherited, and expression is greatly affected by environmental factors (Hagemann and Ciha 1987). Establishing field screening nurseries for identifying cultivars with tolerance/resistance to PHS is costly and time consuming as multiple years and locations are required to confirm results (Anderson et al. 1993). Molecular markers associated with PHS tolerance/resistance would be useful breeding tools for cultivar enhancement.

Efforts to identify quantitative trait loci (QTL) associated with PHS resistance have been ongoing since DNA markers first became available. Anderson et al. (1993) used RFLP (restriction fragment length polymorphism) markers to identify eight QTL using two different mapping populations. Since then, QTL associated with resistance to PHS have been identified on all chromosomes of hexaploid wheat with the solitary exception of chromosome 1D (Kulwal et al. 2005). Nine QTL associated with PHS resistance were identified in Aegilops tauschii (Imtiaz et al. 2008), and DNA markers associated with these chromosomal regions may be useful for introgressing PHS resistance into adapted HW wheat germplasm using marker-assisted selection.

The agronomic performance and end-use quality of HW wheat must equal or exceed that of HRW or HRS wheat for the crop to be a viable option for wheat producers. Grain yields of HW wheat often equal or exceed those of HRW or HRS wheat (Upadhyay et al. 1984; Matus-Cádiz et al. 2003). The bread-making qualities of HW wheat also are comparable to those of HRS wheat (Lang et al. 1998). When milled to a common color standard, flour extraction rates of HW wheat are typically 1–3% higher than those of HRS wheat (Boland and Dhuyvetter 2002). The milling advantage associated with a white seed coat compared to a red seed coat results from the ability to mill closer to the bran layer without leaving visible bran flakes in the flour (McCaig and DePauw 1992). Visible bran flakes discolor flour, and this subsequently affects noodle color (Souza et al. 2004). More HW